Bird-Friendly Windows: Efficient Budgeting BY GREAT SALT LAKE AUDUBON BIRD WINDOW COLLISION WORKING GROUP There is no simple answer to the question, “How much does bird-friendly window glazing cost?” Costs depend on materials, size, window coatings and type of bird protection, among other factors. But here are tips for keeping costs low: 1. Select a stock pattern that fulfills the ABC Threat Factor Rating of 25 or below (American Bird Conservancy, 2023). Some buildings use custom patterns, such as small images of birds, which drive up the price. Most bird-friendly glass suppliers will have a standard pattern with an acceptable threat rating. 2. Protective patterns should be at least 1/8th inch lines or 1/4th inch shapes applied 2 inches apart, ideally on surface 1 (exterior). 3. Advance planning of window widths can save money. Windows are cut from larger sheets. Plan window widths to fit the most windows per sheet to save material and money. Walker Glass provides a nice illustration (2020), seen above. Their bird-friendly glass comes in sheets of 96”x130”, with 1” around each edge reserved for loss. Windows are then cut from the remaining 94”x128” sheet. If the architect asks for 47” wide (or narrower) windows (minus framing), the fabricator can cut two windows from a single width of the bird-friendly glass sheet. 4. A dot pattern maximizes the efficient use of a sheet of glass, compared with lines or other directional patterns. A non-directional pattern, such as dots, allows the fabricator to make cuts from the sheet of glass by orienting the windows either vertically or horizontally on the sheet. A directional pattern, such as lines, does not allow 90-degree turns to maximize the glass area. Again, Walker Glass (2020) illustrates this: 5. Be aware that glass sizes and minimum orders will vary across glass companies and bird protection measures. The three most common bird protection glasses — fritted, etched and ultraviolet — often represent the least to the most expensive choices. But depending on your window sizes, it may be possible to make more efficient use of some products, to keep costs down. For example, one glass company cuts fritted glass from 96”x144” sheets, which may provide a better fit to window dimensions than the 96”x130” in the prior example of fritted glass sheets. One company had a 16-sheet minimum, the other had a 13-sheet minimum. Call the sales representative or find specific information online to understand sheet sizes and minimum orders. 6. These decisions can have a huge effect on costs. For example, if window sizes are not planned well, one might have to order 16 more sheets of glass (the minimum order) to get glass for just one additional window. Sales estimators are reluctant to give cost estimates due to all the variations imposed by sizes, total order volume and materials. But they note that costs can range from 10% more to more than double the cost of windows that are deadly to birds. Questions? Email Barbara Brown at barbara.brown@fcs.utah.edu. 1. American Bird Conservancy. (2023). About the ABC Rating System. https://abcbirds.org/wp-content/uploads/2025/02/What-is-a-Material-ThreatFactor-2-18-25.pdf. 2. Walker Glass. (2020, 10/22/2020). Bird Safe Glass – design rules to meet your budget and minimize bird collisions. Blog. https://www.walkerglass.com/blog/bird-safe-glassdesign-rules-for-budget/. 3. For a general list of products that have been safety tested for birds, please see the list maintained by the American Bird Conservancy at https://abcbirds.org/glass-collisions/ products-database/. 26 REFLEXION
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